Note that the following discussion refers to a number publications and references. Discussion of such publications herein is given for more complete background of the scientific principles and is not to be construed as an admission that such publications are prior art for patentability determination purposes.
On 20 Apr. 1999, two students at the Columbine High School in Littleton, Colo. opened fire on their classmates and teachers with assault weapons. Twelve teenagers and one teacher were killed, and dozens of others were wounded. Tragic acts of violence like the Littleton massacre occur all too often in present day America. The Federal Bureau of Investigation reports that every year, criminals in the United States use firearms to commit over 2.4 million robberies, 5.6 million assaults, and 165,000 rapes. (See American Firearms Industry Journal, published by the National Association of Federally Licensed Firearms Dealers) The Center for Disease Control has collected data showing that 247,979 “firearm deaths” were recorded in the United States during the years 1986–1992. (Data compiled by the Center to Prevent Handgun Violence.) Furthermore, in recent years, a new threat has evolved; that is the suicide bomber. These are more dangerous and more devastating and because of the nature of their weapon, it is imperative that they be detected at a long distance.
Many previous efforts to reduce the threat posed by the criminal use of firearms have met with limited success. In the past two decades, very expensive x-ray equipment has been installed in major airports. The machines are generally capable of detecting a metal gun in a very specialized, closed environment. This type of equipment requires a fixed installation, occupies a very large space, is close-range and may cost hundreds of thousands or even millions of dollars.
None of the complex concealed weapon detectors that are currently available in the commercial market are compact, lightweight, portable, easy to use, long-range and highly reliable. The development of such a device would constitute a revolutionary achievement and would satisfy a long felt need in the fields of law enforcement and security.
Earlier versions of the present invention are described in U.S. Pat. No. 6,243,036, issued Jun. 5, 2001, entitled “Signal Processing for Object Detection System”, U.S. Pat. No. 6,359,582, issued Mar. 19, 2002, entitled “Concealed Weapons Detection System”, International Patent Application Number PCT1US97/16944, entitled “Concealed Weapons Detection System”, published on Mar. 26, 1998 as International Publication Number WO 98/12573, and International Patent Application Number PCT/US00/14509, entitled Signal Processing for Object Detection System”, published on Dec. 14, 2000 as International Publication Number WO 00/75892. The specifications and claims of these references are incorporated herein by reference.